aitken



6 Sheets-Sheet l- No. 198,725. Patented Dec. 25,1877.

FIG'.I.

FIG-2.

live/7e67, HM v w hcy 7, l z {1.1M

. N. PETERS, PHbTO-LiTHOGRAFHER. WASHINGTON. D C.

m 6 Sheets-Sheet 3. H.-AITKEN & W. YOUNG. Process for Manufacturing Illuminating-Gas.

No. 198,725 Patented Dec. 25,1877.

N. PET-m. PHOT'O-UTfiOGRAPHEX, WASHINGTON, D, c.

l 6 Sheets-Sheet 1L. H. AITKEN & W. YOUNG. Process for Manufacturing Illuminating Gas.

N o. 198,725. Patented Dec. 25,1877] NFETERS, FHDTO-LITNOGRAPHER. WASHINGTON I10.

6 Sheets-Sheet 5. H. AITKEN & W. YOUNG. Process for Manufacturing Illuminating-Gas.

Patented Dec. 25, 1877.

-I I i N- PETEPS, PHOTQlITHOGRAPHEI T, WASNINGTGM D. C.

6, Sheets-Sheet 6.

H. AITKEN 8: W. YOUNG. Process for Manufacturing Illumin Mpg-Gas.

N0. 198,725. Patented De 25,1877.

-Ph'ERS. FNOTO-LITHOGRAFHER. WASHl N GfON n. c.

N E 'j T -Esi in whom 5t mag concern 'Be it known thatjwe, HENRY AITKEmbf PATENT OFFICE.

v "nn unr Arrnnmor r LKinmANn Y 1 g i arri uni,

I Q lMPROl EMENllN PROC SSESFORQMANUFACT RINGlL umlii rme-eAs;

l vS )ecification forming partoi' Letters Pa tent No 1 9 S,725, dated December 25,1877 application filed v 31 1September2,1S7 6.

Falkirk, in the countyof Stirling, North Brit ain,fcoalrnaster,- H IILl YWILL IAM YOUNG, of

Olippens, in the county Britain,

oil works manager, have invented Improvements in ,th e Manufacture of Illum i-f nating Gas, of which theffollowling isajs'pech ,ffication: i i This invention,-which relates to improve ments in themanufacture of illuminating-gas; has for its object as ifollows i iliirst, to effect the more perfect and complete applicaticnfor. the manufacture of illuminating-gas of the liquid volatile hydrocarbons produced andor-idinarily left in the tars-Whencoal, shale, li v;

drocarbo'n oils, resin,orother bituminous substances are destructively distilled for the? proin duction of illuminating-gas and, secondly, to

effect the economical use of the fixed] carbon contained in the coke, resulting from the de-j 1 structive distillation of bituminous substances, j; 7 having combined or mixed Withthe n a large uantity of mineralxmatter, and also to re-i move andutilize the carbon deposited in and} on the, surface of gasretorts. i

h uiearboiiprocess} t e difficulty hitherto Vi experienced in, the practical or commercial working, of which has" principally been the production of a gas havinga uniform illumii nating power; This diflicultylarises from the i Want of efficient means for regulatingthefsup- With of thefor ns arrangementsof apparatus hitherto employed it has been es,

sentialthatthe water gas'should be passed into the bituminous retortwhil'e the bitumiinous substance is undergoing distillation, or'

mingled with the Warm crude bituminous gases as they are produced, andin as nearas possible the proportion' necessary to combine at once with the hydrocarbon Vapors as theyare produced'from thebituminous substance, for,

in the event of the water-gas being int'oo of Renfrew, North j i The accomplishment of the aforesaid objects gfconstitutes, essentially, the practical Working of what isfwell known to. gas-engineers as the large a quantity, the resulting mined gases haye been deteriorated in their illuminating power by diluting the bituminous gases atoo lmuch. Onthe lother-l'iand, in the event of hydrocarbonshave not been all taken up and diffused through the mixed, gases, and have dant at the early stages of the distillation,

stages, they i are almost entirely wanting, it is easily perceived thatconsiderable dififieulty 1 obviated, or in a great measure modified, and

by utilizing the means hereinafter described. Figure1,Sheet 1, is a section, partly in elevation, :of an arrangement of apparatus for carbonic oXide,) or other gas havinga low illuminating power, in one set of retorts, which isafterward passed through a secondset of retorts, in" which" bituminous coal or other similar substance is being distilled, and the combined gasessubjectedto the action of the analyzer or practical condensing arrangement;

at one nside,but which is not shown in the hopper 4; and then opening the valve 5, by decarbonaceous matter falls into the retort. ,The

and steam is admitted thereinto in a regular regulatingwalve, I0, actuated by the lever 11,

e, or cnn rnns, NORTH the water gasbeing deficient inquantity,'the

thereforebeen condensed and removed by the tars, A's during the distillation of a charge of coal thc hydrocarbons produced suitable* for being so takenup by Water-gas are coni stantly altering in quantity, being most abunan gradually diminishing 'ui ui, ill ilhla ittel occursin regulating thesupply of water-gash, By the present invention those defects are i the hydrocarbon process made a valuable one,

the manufacture of Water-gas, (hydrogen and v i The retorts 1 and 2, for the production of the Watergasj'or other poor gas, are set in a vertical position, and heatedby a furnace placed drawing, The carbon necessary for the de composition ofthewater is introduced by the i hopper and valve arrangement 3, by filling the pressing the lever 6, when the coke or other v retort 1 is kept at a very high temperature,

stream by the valve :7 communicating withthe inain steam-pipe n8,ledjfrom the steam boiler 9, 1 v y On this main steam pipe 8 there is placed a connected to a small governin g gas-holder, 12,

being raised rlowered by the press-Q l ure ofthe gas passedby the pipe 13, regulates the quantity to be admitted for the pro ,passes'up through the coke or carbonaceous matter into the body of the retort l, where it isdecomposed into water-gas, and is then drawn off byv the outlet-pipe 15, and passed to.

the hydraulic main 16 and condensers 17 wherein any water which may have escaped decomposition is condensed, and removed by pipe 18. Should the carbon employed for decomposing the water contain sulphur, the gas may be also purified to remove sulphur com-- pounds present, and after being so purified it is then passed through the meter 19 to be measured, and thence to the main pipe 20, for

supplying the bituminous gas-retorts 27.

i The bituminous gas-retorts 27 may be of the ordinary horizontal description. The water- ,gas or other poor gas is admitted to the bituminous retorts by the pipes 21 and 26,1eading from the main gas-pipe 20 through the screw- I valve 22. To admit the water-gas automati- 1 I 'callytheapparatus shown on an enlarged scale at Fig. 2, Sheet 1, is employed, this being so constructedthat the pressure of the gas on the retort being charged lifts the small gasholder 23, which actuates the valve 24, covering the pipe 21,and thereby allows the watergas, which is kept or made under a considerably greater-pressure, to 'pass by the pipe 26. to the bituminous retort. f On the pressure being removed from the retort, the small holder. 23 at once falls, and shuts off the supply of water-gas.

The mixed bituminous andwater gases pass off by the stand-pipe 28'to the hydraulic main 29, and thence by the pipe 30 to the analyzer or fractional condenser A, which may partake .of a varietyof forms. The analyzer or fracj tional condenser A shown at Fig. 1 is considered by us to be among the best forms of this apparatus, and it is very similar to the ordinary Coffey still-analyzer. This analyzing arrangement consists, as will be seen on referring to the drawings, of a vertical tower or chamber, having tray-dia'phragms 31 placed at intervals, and so arranged that the gases in their passage between these trays are caused to'travel, in a tortuous course, alternately from the sides to the center, the apertures through which the gashas-to pass being alter,

nately at the sides and the center of the trays.

Hanging from the edges of the central part of the trays, and dipping into thetars in the trays underneath, are tubes of wire-gauze 32. Perforated metal or an equivalent porous arrangement may be adopted. Two of the lower trays 31 and bottom 31 of the tower are shown cased or doubleybut more of the trays may also be so constructed; and into this space steam is admitted by the pipe 33, con nected to the steam-boiler 9, and the con densed water is drawn off by the pipes 3a and valve 35. I

\ The combined bituminous and water gases or other non-luminous gases, with the suspended crude tars, on entering the fractional analyzer or condenser by the pipe 30, pass under the lowest tray 31, and over the surface of the heated tars in the bottom of the analyzer,

and so that they are bathed in a large volume of the comparatively volatile vapors of the hydrocarbonsgiven off from the heated tars,

whichcauses the heavy tarry particles sus-.

pended in the crude gases to be partially deposited. The gases then travel over the first tray, 31, and through the wire-gauze tube'32,

hanging from the edges of the aperture in the second tray, 31, which effects a further'sepa'ra tion of themechanically-suspended tars,'and at the same time the gases receive lighter hydrocarbon vapors from the tars flowing over the wire-gauze 32 from the second tray. This process is repeated by the passing of the gases through the second wire-gauze and over the surface of the heated tarsvcontained in thethird tray, and so on, ascending fromftray to v tray.

are successively heated to a less degree. The ascending gases; becoming gradually cooled, deposit heavy hydrocarbon vapors and receive lighter ones, until, by the time they reach the outlet-pipe 36 leading to the; scrubbers, they have parted with all,' or nearly all,

their tarry particles, and only contain those vapors of hydrocarbons diffused through them, most of which remain permanently suspended, a small portion only being removed by the scrubbers, which is again returned by the pipe 37, to be used in carbureting a fresh quantity of gas.

At the same time that the gases are being deprived of tarry particles and receiving volatile vapors the deposited tars and condensed heavy hydrocarbonvapors descend from tray to tray, and, as already described, repart with any absorbed vapors sufficiently volatile to the ascending current of, gas, until, by the time the tars reach the bottom, they are almost or.

practically denuded of volatile hydrocarbons, and pass away by the pipe 38 to the tar-tanks.

The figure on Sheet 2 of the drawings is 'a section, partly in elevation, showing how the process may be conducted by the alternate production of bituminous gas and water-gas in the same'ordinary horizontal retort. When the illuminating, or bituminous gasis madefrom'coal or similar solid material, the retort 27 is first charged with the substance, and

the destructive distillation completed, or nearly so, the gas passing away by the stand-pipe 28, hydraulic main 29, and pipe 30 to the analyzer Thetars contained in' the succeeding trays A,.heated bythe steam-pipe 33, connected to the steam-boiler 9, and there subjected to .treatment, as hereinbefore described, only inthis case the bituminous gas leaves behind in the condensed tars hydrocarbons which can be. taken up by a poorgas. The poor or water."

gas is made by opening the valve 7 on the pipe 8, connected to the steam-boiler 9, heated by partially-spent heat in themain flue 39. The steam, entering the retort 27, comes into contact. with the carbon (graphite). deposited on the surface of the retort, and that contained in the residual coke, and is thereby decomposed in to hydrogen and carbonicoxide, which, in turn, is passed by the outlet-pipe. 28, hy draulic main 29, and pipe 30 to the analyzer A, and therein, coming into contact with the heated tars contained in the-trays, takes vup the volatile hydrocarbons left in the tars bythe bituminous gases. The deposited carbon (graphite) is thus removed from theretort and utilized, and the retort itself is thus kept clean and efi'ective. i l I I When the bituminous substance employed for the production of the illmninating-gasl is a liquid, such as mineral oil, or a solid which may be melted and kept liquid at conveniently low temperatures, such as resin, the-process is slightlymodified, the retort being charged with coke, broken brick, scrap-iron,or other substances presenting a large surface, andthe mineral oil or other bituminous liquid is led.

into the retort 21 by opening the valve 40 on thepipe 41 connected to the tank 42. The oil, as is .well known, on entering the retort, is immediately volatilized, and in its passage through or among the highly-heated solid matter in the retort is decomposed and converted into crude illuminating-gas, solid carbon being at the same time deposited on the surface of the hot solid-substance and on the surface of the retort. The oil-gas passes away to the analyzer, where the condensable portion isremoved. At intervals the admission of oil is stopped, and steam admitted, as before, from the boiler 9. r This steam is decomposed by the carbon deposited from the oil, and the resulting gases passed through the analyzer to take up the surplus hydrocarbons condensed from the rich oilgas. Both gases are afterward blended or mingled in the gas-holder and instead of introducing steam ready formed into the retort, water may be run in directly and converted into steam inside the retort; but it is preferable to pass in the steam ready formed. The figure on Sheet 3 is a section, partly in elevation, of anarrangement where the process is conducted by the simultaneous production of bituminous and water gas in one retort, but which may also be modified, so as to producethese gases intermittently; This. ar-

rangement is more particularly designed for the distillation of coal,-shale, and similar substances containing a large percentage of ash, but which give a gas of considerable illuminating power. The retort is similartothat al- Lready referred to with reference to Sheet 1 for 'theproduction of. wateng-as, havinga vertical "limbor portion, 1, and a horizontal limb or portion,2. Thelatter isquite. filled with coke,

and the former to the extent of two-thirds, or

thereabput. V l v The, bituminous-shale, coal, or other, substance is charged by the hopperv 3 and valve 7 5 into the. remaining or upper third part of the 1 vertical portion of the retort, and there dis- :tilled jinto, crude illuminating gas. At the same time steam is admitted into the horizon- ;tallimb, or portion of the retort 2 by opening the valve 7 onthe pipe -8 leading from the steam-boiler '9. ,This steam, in its passage through the highly-heated coke, is decomposed, producing .watergas, which combines and 1 m'ingles with the rich bituminous gases asthey are producedfrom the shale, coal, or analogous substance, contained inthe upper third part of theretort. 7. e a f.

The combined. gases pass by the outlet-pipe 15..- to the hydraulic mainlfi, and thencebythe pipe 30, to the analyzer, and are therein subjected to the treatment hereinbefore described.

, As soon as the first charge of shale ,or. other bituminous substance is 4 nearly worked off some of the ash is drawn fromthe bottom of the retort inthe water-trough 14, and a fresh ing into the retort the, oil in a stream above and passing water-gas up, and commingling it with the oil: gases as they are produced,

, using the deposited carbon from the oils for the production, or to assist in the production, of thiswater-gas, or by making the process. intermittent by shutting off the steam by the valve 7 from the horizontal portion. of the retort, and admitting oil by opening the valve 40 connected by the pipe 41 with the oil-tank 42. r The oil, on entering the horizontal portion of the retort, is volatilized, and decomposed in passing up through the heated solid matter charged into the vertical limb or portion 1 for,

the purpose;- So soon as the interstices between the highly-heated solid substances become so far closed as to impede the flow and .production of the oil-gas, the oil is shut off,

and the steam again admitted, which is de composed and removes the carbon deposited by the decomposition of the oil. In both cases the, gases. are subjected to treatmenttin theft analyzing arrangement-A, in the manner described. In practical working this process is repeated, alternately. admitting oil and steam. k The figure on Sheet 4 of the appended drawings is a section, with parts in elevation, showing an arrangement for the production in separate retorts of the bituminous and non-lumi-v nous gases, and for the simultaneous and separate treatment of both gases in a combined analyzing arrangement. The watergas and bituminous gas-retorts and the analyzer are similar in construction to those hereinbefore described in reference to Sheet 1, and similar numbers refer to similar parts of the apparatus. The gases are also produced in a similar manner; but, instead of combining the different gases in the bituminous retorts, they are kept separate and carried into the analyzer in two separate currents, the crude bituminous gases and tars being introduced, as shown, by the pipe 30 between the fourth and fifth tray from thebottom of the analyzerA. At the same time the water-gas or other poor gas is introduced by the pipe 20 at or near the bottom of the analyzer. Both gases pass upward from where they are admitted. The bituminous gases, as they enter from the hydraulic main 29 by the pipe 30, are warm, and are further raisedin temperature by the heat of the water-gas ris ing up from below. The mingled gases are thus subjected to the analyzing action, hereinbefore described, in their tortuous passage through the higher trays and wire-gauze tube in the analyzer. At the same time the tars and condensable heavy vapors deposited from the gas in the upper portion of the analyzer fall back from tray to tray until they drop through into the trays 31 in the lower part of the analyzer, wherein they are heated by the steam, as before described. At this place the heated tars are acted upon by the incoming current of water-gases or other poor gases, and any traces of hydrocarbons which may remain. in the tars, and which are sufficiently volatile, are taken up by the gas, and the tars pass away denuded, as far as practicable, by the pipe 36 leading to the tar-tank.

The figure on Sheet 5 shows an arrangement of double-ended or through retorts, by which the process of making illuminating-gas according to thisinvention may be conducted in several ways. By one mode the retorts 27 .a'nd27 are charged to the extent of one'half with the bituminous substance, the other half being filled with coke. The hydraulic valve 29 in the stand-pipe 28, leading from the end of the retort. filled with coke, is lifted and closed, and the hydraulic valve l6" on the pipe leading from" the opposite end of the retort is lowered and opened. At the .same

time the lowering of the valve 16 actuates the rod 43, connected to the valve 44, which admits steam from the steam-boiler 9 by the pipe 45 and stand-pipe 28 into the end of the and the mixed bituminous and water gases pass away by the stand-pipe 28 to the hydraulic main 16, and thence by the pipe 20 to the analyzer, to be there subjected to treatment in the manner hereinbefore described. So soon as the first charge of bituminous substance is exhausted the valve 16 is closed and the coke removed from the end previously employed tomake the water-gas,'and replaced by a charge of the bituminous substance. The valve 29, being now lowered, opens the valve 46 and admits steam from the boiler 9 to the opposite end of the retort 27, which contains the coke from the previous charge of bituminous substance, and by which the steam is at once decomposed into water-gas. This water-gas, in turn, passes over the fresh charge of bituminous substance in the end of the retort- 27 and by the stand-pipe 28 to the by ,draulic main 29, and thence by the pipe 20 to the analyzer. This process is repeated, alternately charging the reverse ends of the retort with the bituminous substance, and using the coke on the opposite end, derived from the previous charge of bituminous substance, to decompose the water for supplying the water-gas to take'up the surplus hydrocarbons that would be left in the analyzer by the bituminous gases.

Instead of making the water-gas in one endof the retort, any substance, such as spent bark, sawdust, peat, or others giving a large proportion of poor gas, may be employed to produce the gas to take up and utilize the volatile hydrocarbons, the bituminous sub.-

stance being charged at the same time, and the poor gas from the other substance caused to pass over and out by the same stand-pipe, together with bituminous gases.

Another mode of working the process is similar to, that already described with refer. ence to the figure on Sheet 3 of the drawings, and it is conducted as follows: connecting the lever 48 of thehydraulic valve 29 on the stand-pipe 28, and the steam-valve 46 on the "pipe 49 leading from the steamboiler 9, is disconnected. The entire length of the retort is now charged with. the bituminous substance, and the crude bituminous gases are passed away by the stand-pipe 28 into water-gas, and drawn off 'by the stand:

pipe 28 into the hydraulic main 16 and thence passed by the pipe 20 into the bottom of the analyzer. The retorts are so worked that about one half of them are producing water- The rod 47.

power.

gas during the time the other half are producin g bituminous gas, and thetwo gases are collected, in the manner described, in the separate hydraulic mains, being afterward separately and simultaneously heated,'as hereinbefore described in reference to the figure on Sheet 4, in the combined analyzing apparatus A.

By athird mode of making gas according to this invention, with the" apparatus shown on Sheet 5, the bituminous gas may bepassed into ordinary condensers, as shown by the dotted pipe 30 and at- 51, Sheet 5. The condensed tars are run off by the sealed pipe 52 to the tar-well 53, and the tar is pumped from thence "by the pipes 54cand pump 55 to the top of the analyzing apparatus A. 'At the same time the water-gas is passed by the pipe 20 through the analyzer, and takes up the 'surplus hydrocarbons contained in the pumped tars from the bituminous gases. The resulting gases'may be either kept separate and used separately, or, as shown in the drawing, combined by the connecting-pipe 56, and passed on to scrubbers and purifiers together by the pipe36.

The drawing on Sheet 6 exhibits an arrange ment of gas apparatus which may be in many cases advantageously employed to carry out the process, more especially where it is desired toreducethe tars to a semi or wholly pitched or solid condition, and when the gases "are not required to have avery high illuminating The retortshown is specially adapted for the production of gases suitable tobe treated by this process from shales, coals, andsimilar substances, giving bythe ordinary process of gas-making a gas of very high illuminatingpower. The retort consists of three connected limbs or parts, 1, 2, and 3.: The bottoin'limb 1 is kept charged with the coke from'shale or other substance distilled. The limb 2 is charged with similar coke or anthracite coal, bricks, or scrap-iron, or any ma terial capable of resisting a high heat and presenting a large surface. The higher limb 3 is charged bythe hopper and valve 4; with bituminous substance,'the crude illuminatinggases from which pass downward into the limb 2. At the same time steam is admitted into the bottom limb 1 by opening the valve 5 on the pipe 6 connected to the steam-boiler -7. This steam, in passing upward to the limb 2, undergoes decomposition by coming into contact with the carbon contained in the shale or other coke. The two gases (bituminous and water gas) mingle and blend on entering the limb 2, and the undecomposed liquid hydrocarbons contained in the bituminous'gas undergo a further decomposition in the presence of the'water-gas by coming into contact with the surface of the heated solid material through which they have to pass. As soon as the first charge is exhausted spent ash is drawn from the bottom of the retort resting the temperature necessary.

in the water-trough 8. This empties, or partially empties,jthe upper limb of the'retort, which is again filledwith a f'resh charge of bituminous shale or other gas-producing material. This processis continuouslyrepeated. The combined gases pass off by the stand-pipe 9 to the hydraulic main 10, and thence by the pipe ll'to the analyzing apparatus 12, which consists of'a-horizontal still or chamber divided by a series of partitions, 13, in such a manner as to cause the gases and tars topass in a tortuous manner from'one end of the chamber to the other, the tars and gases passing in opposite directions, as shown by the ar rows. Underneath this chamber or analyzer is placed a furnace, 14, by which the tars'and gases may be heated to the required tempera ture, according to the quality of pitch desired. The harder the pitch required the higher is a The gases enter this analyzing apparatus by the pipe 11, and undergo very similar treatment to that described in reference to the working of the analyzing apparatus shown on the two preceding sh'eetsof drawings. The gases, as they pass from division to division of the apparatus 12, deposit heavy vapors and tar parcles, and take up lighter hydrocarbon vapors, until, on leaving the analyzer by the pipe 14?", they are almost freed of tars proper, andfcontainonly' vapors of the more volatile hydrocarbons derived from the tar.

To enable the gases to hold those comparatively-heavy hydrocarbon vapors, they pass from the analyzer more or less heated, and thence through the coolers or condensers 15 5 or, where the temperature is very high, a see 0nd vertical analyzing apparatus may be'employed to reduce the temperature of the gases. The condensed matters, ammoniac'al liquor, and liquid hydrocarbons are run off, thefor+ mer into the liquor-tank to supply thescrubbers by the stop-cock 16, and the latter can either be returned by the cock and funnelpipe 17 to the horizontal analyzer, or disposed of as heavy tar-naphthadirect. The analyzed tars or pitch are from time to time run off from the analyzer 12, by the cook 18, into a sand-bed or otherform of mold to be cooled. The tar is led from thel ydraulic main 10 into thechamber 12 by the pipe 19. l I

In working this invention by any of the 'hereinbeforedescribed or analogous arrange.

ments of apparatus, the quantity of hydrogen and carbonic oxide or other gases having a low illuminating power necessary to take up the hydrocarbons from the crude gases pro.- duced from any given bituminous substance,

and to produce a gas of the desired illuminat- I ing power, must first be ascertained by trial, through distilling a given weight of thebitu .minous substance, and adding the water or other gas until the desired illuminating power is attained. Y i l a l Although, in carrying out this invention, it

is not essential that'the water-gases and bi- -tuminous gases be made at the same time, because the action of the analyzer upon. the gases is such that considerable variations may be made between the proportion of the bituminous and non-bituminous gases at the illstant of their production; for, should the quantity of hydrogen or other non-luminous gas be insufficient to take up the whole of the hydrocarbons produced together with the bituminous gas at the time, the surplus falls backinto the trays of the analyzer; and, on the other hand, when the hydrogen or other non-luminous gas is more than sufficient to take up the hydrocarbons from the bituminous gases simultaneously produced, then the previously-conden sed surplus hydrocarbon vapors contained in' the trays serve to supply this deficiency. The variations in the proportions of the gases are in this manner practically balanced by the action of the analyzer. Yet, where it can conveniently be done, it is better that the water-gas should be passed into the bottom of the combined analyzer in as regular a proportion as possible to the bituminous gases, so as to meet the stream of crude tars contained in the surplus hydrocarbons as they drop from the portion of the analyzer in which the bituminous gases are analyzed and condensed; or, where it is desirable to analyze the mixed gases, the water-gas should be passed into the retort containing the bituminous matter, and there mingled with the crude bituminous gases as they are eliminated, as it appears the poor gases serve to shield from overdeconiposition the hydrocarbons present in the crude bituminous gases suitable for carbureting the poor gases. Therefore, in adding the poor or water gases ascertained to be necessary to take up the hydrocarbons from the bituminous substance and form the quality of gas'desired, the valves for admitting the water-gas, or the steam for its production,.or

other poor gas, should be regulated to pass as near as possible the average necessary quantity during the distillation of the weighted bituminous substance. A very short time will suffice to do this,-checking the quantity added by the meter, measuring the water or other poor gas alone, or by taking the gross quantity' of mixed gases passed through the ordinary station-meter.

If desired, the improvements in the manufacture of gas constituting this invention may be worked with a lower temperature of the analyzer by reducing the pressure of the gas or vapors therein to any desired point below that of the atmosphere. This maybe effected by the use of an exhauster, steam-jets, or the mechanical equivalent thereof, placed between.

the analyzer and the scrubbers, regulatingvalves being placed between the analyzer and the retorts, to prevent too much reduction of the pressure in the retorts, or a considerable portion of the force or energy required to relieve the gases of the atmospheric pressure may be utilized by passing the hot vapors and gases as they leave the hydraulic main through a supplementary cylinder or cylinders actuating. a piston or pistons attached to the driving-gear of the exhauster, the said gases being worked more or less expansively,

according to the pressure desired in the re-.

torts. I

Under this method of working, the atten'; uated hydrogen or other gas of low illuminating power that may be used is rendered capable of absorbing a large volume of the hydrocarbons.

Having now described and particularly as certained the nature of our said invention, and the system, mode, or manner in or under which the same is or may be carriedinto practical effect under various modifications, we wish it to be understood that we do not confine or restrict ourselves to the precise details or arrangements we have had occasion to describe and delineate, as many variations'may be made therefrom without departing from the main or essential features of our said invention. .Neither, on the other hand, do we claim as new, or as our invention, thedecompositionof water into carbonic-oxide and hydrogen gases by highly-heated carbon contained in gas-retorts, nor do we claim the combining the carbonic oxide and hydrogen'so obtainedwith .the crude gases, as-they are produced from bituminous substances undergoing dis-. tillation, either in the bituminous retort or out of it while warm; nor do we claim the carbu-v reting of hydrogen and carbonic oxide obtained from the decomposition of water by heated carbon or other gas having a low illu-:

,minating power with the diffused vapors of I hydrocarbons in an isolated form, as we fare aware that this has been previously done to some extent for the like purpose to this invention, as we have already stated, by meansIof what is known as the hydrocarbon-process, and by other means. the details of mechanical 'construction'separately which we have had occasion to describe and refer to, (as manyof these are already in use,) except in combination with and as forming parts of the essential features,and for the objects or purposes, of our said invention; but What we consider to be novel and original, and therefore claim, is

1. The process of manufacturing illuminating-gas by carburetin g water-gases, in diffusing them in regulated quantities through independently controlled or separate retorts, wherein hydrocarbon vapors are being evolved from bituminous substances, thus preventingthe deposition of carbon in the retorts, or, if

already deposited, utilizing it, substantially as described.-

2. In the manufacture of illuminating-gas,

the process herein described of diffusing or suspending in and through hydrogen, carbonic-oxide, or other gas or gases'havmg a low illuminating power, the volatile hydrocarbons produced, and ordinarily left in the Neither do we ,claimall tars when. coal, shale, hydrocarbon oils, resin, or other similar bituminous substances are destructively distilled for the production of illur'ninating-gasthat is to say, bringing the said hydrogen, carbonic-oxide, or other poor gases into contact with the tars while in a heated state and spread over large surfaces, or by mingling the said gases with bituminous gases, either in the bituminous retort as they are produced or afterward, and subjecting the mingled gases to fractional condensation or cooling, the condensed tars being kept'in a heated state, substantially as hereinbefore shown and described.

In witness whereof we have signed our names to this specification in the presence of two subscribing Witnesses.

HENRY AITKEN; [L. s.

Witnesses:

DAVID DRYSDALE AUs'rIN, GEORGE MAGAULEY CRUIKSHANK.

J WILLIAM YOUNG. [L. s.-j I 

